Abstract : The second-order susceptibility describes the energy transfer of second-order nonlinear optical effects in media with non-central symmetry. In the waveguides made of this kind of media, however, if the phase-matching condition is not satisfied, the effects are very weak in the propagation distance that the wave interaction length is much longer than the coherent length (the wave interaction length can be very long, when the guides have low loss.). It is theoretically demonstrated here for the first time that the waveguides in this case can support the envelope solitons described by nonlinear Schrodinger equation (NLSE).